Some new EIGRP feature_ server

1. Stub
Prevents the router from sending unwanted query, and when a router is set to a stub, the other routers will not send him query.
You can set which routes to declare (connected, redistributed, static, summary, or receive-only)

2. Stub leaking
---+----------------+----

R1 R2

| |
e0/0| |
R3---------------R4
E0/1 |
---+----
192.168.1.0
R1,R2 the default route to R3,r4, R3 and R4 belong to a remote site and are set to stub. When the R2-R4 link down, because the r3,r4 are stub, so do not send query each other, then R4 will not declare 192.168.1.0 to R3, R3 will not declare the default route to R4. At this time 192.168.1.0 the network is completely not up.
Then you can R3,r4 is a stub, set the R3 to R4 leak a default route, R4 to R1 leakage 192.168.1.0.
Configure the following command on the R3
Access-list 1 Permit 192.168.1.0 0.0.0.255
Access-list 2 Permit 0.0.0.0 0.0.0.0
!
Route-map leaking Permit 10
Match IP Address 1
Match Interface e0/0
Route-map leaking Permit 20
Match IP Address 2
Match Interface E0/1
!
Router EIGRP 100
EIGRP stub Leak-map Leaking
Similarly, in R4 to R3 interface on the R3 leakage 192.168.1.0. So the above problem is solved.

3. Summary leaking
10.1.10.0/24 10.1.20.0/24 ... 10.1.250.0/24
----------------------------------------------------------------------
/       \
/           \
/               \
10.1.1.0/24|-----R1-----------R2-----|10.1.2.0/24
\               /
e0/0 \/e0/0
\       /
\   /
R3
As shown in the figure, require R1, R2 the top of the network rollup for 10.1.0.0/16 sent to R3, and for the R3 can choose the best path to 10.1.1.0/24 and 10.1.2.0/24, R1 and R2 also need to put their direct connection 10.1.1.0/ 24 and 10.1.2.0/24 proclaimed to R3. For such a situation, the previous practice was:
R1:
Interface e0/0
IP summary-address EIGRP 100 10.1.0.0 255.255.0.0
IP summary-address egirp 100 10.1.1.0 255.255.255.0
After using summary leaking:
R1:
Access-list 1 Permit 10.1.1.0 0.0.0.255
!
Route-map leaking Permit 10
Match IP Address 1
!
Interface e0/0
IP summary-address eigrp 10.1.0.0 255.255.0.0 leak-map leaking

4. Summary only
10.1.10.0/24 10.1.20.0/24 ... 10.1.250.0/24
----------------------------------------------------------------------

R4
/   \
/       \
/           \
/               \
R1-----------R2
\               /
e0/0 \/e0/0
\       /
\   /
R3
Requires R1,R2 to summarize its upper network as 10.1.0.0/16 sent to R3 and, for security reasons, does not want R3 to know the link r1-r4 between R2-R4 and 192.168.x.x, the original practice:
R1 on the e0/0 to do summary, and configure Distribute-list, only allow 10.1.0.0/16 sent to R3
You can now do this:
R1:
Interface e0/0
IP summary-address EIGRP 100 10.1.0.0 255.255.0.0
IP summary-only EIGRP 100

5. Stub co-existence
Hub Router

--------------------------------------

R1 R2 R3
In Multi-access network, if R1 is stub router, then R2,r3 must also be stub router, otherwise hub router will still send query.
It was originally used to manually specify Neighor to avoid this problem, but this is very poor extensibility, and manually specify neighbor can only use unicast and will reject the multicast package. So each additional stub in the Multi-access network Router must add a neighbor command to the hub router.
After improvement:
* Hob Router Use multicast pack
* Spoke router even if manually configured neighbor can also accept multicast packets, so that in the Multi-access network part of spoke router can be used unicast, part spoke router with multicast
* In Multi-access network, hub router will not send query to stub router, for Non-stub router, hub router will send query
* In the Multi-access network, if you use unicast to non-stub router to send query, and the number of non-stub router more than 5 or 10% of the total, efficiency will be very low, encounter so many non-stub Router, it is recommended to use multicast to send query.

6. IEGRP support Graceful restart,  as summary, distribute-list and so on,  will not re-establish the neighbor relationship,  But to do graceful restart.  if you do not support peer resynchroniazation,  Nsf-restart